Conventionally, an information processing apparatus such as a personal computer or the like has connected to the connector thereof an adapter device in which a memory IC card used as an external storage unit can be set or the like as the case may be. The connection of the adapter device to the connector of the information processing apparatus is made by a USB interface, for example. By operating the information processing apparatus, the user can play back content data such as video data, music data or the like stored in a storage unit in the information processing apparatus by storing the data into an IC card set in an adapter device, setting the IC card having the content data thus stored therein into a portable information processing apparatus and reading the content data from the IC card. The user can thus enjoy the content data anytime and anywhere.
In addition to the memory IC card used as an external storage unit, there is currently available a variety of such modules having different features. The IC cards are used as a feature expansion module for the information processing apparatus as a host apparatus. For example, the IC cards include an access management one which manages the access to the information processing apparatus as a host apparatus by checking the fingerprint, as one of the biological features, of the user trying to access the information processing apparatus. Such IC cards having different features are unified in profile and interface except for their unique-functional portions, and the adapter device has an IC card receptacle in which there can be set any one of a plurality of IC cards of different functions. For example, the fingerprint recognition IC card and memory IC card are similar in profile, outside dimensions, interface and the like to each other but they are partially different from each other. Namely, the fingerprint recognition IC card has a fingerprint detector provided on one main side thereof, while the memory IC card has attached on the main side thereof a label on which its stored content is written down.
Since there is set any one of IC cards having different functions, the adapter device should be designed in profile etc. so that the IC card set therein will not interfere with the operation of the adapter device.